News and views on autism research and other musings. Sometimes uncomfortable but rooted in peer-reviewed scientific research.

Thursday, 19 September 2013

Autism and the GFCF diet: ScanBrit episode 2

"These preliminary observations on potential best responder characteristics to a gluten- and casein-free diet for children with autism require independent replication".

That sentence, taken from a recent (pre-print) publication I was very peripherally involved in writing, is probably the most important thing to take from the paper by Lennart Pedersen and colleagues* and certainly is a message that I would be very keen to promote.

Skandinavism @ Wikipedia

ScanBrit, was/is a meeting of minds between the group I work with and other research groups based in Denmark and Norway, who wanted to experimentally examine the question of whether a diet devoid of foods containing gluten and casein might be able to impact on the presentation of autism in children.

In the most recent paper, (we) the ScanBrit collaboration were looking to further analyse the wealth of data which was generated over the course of the 2 years of experimental study and in particular, try and ascertain whether there were certain characteristics which might be markers for dietary response or not. As any person following the GFCF diet or their parents know, this is not an easy diet to follow and might, under certain circumstances, place a person at risk of nutritional deficiencies (see here) and/or other more socially-mediated issues (see here). Identifying markers of who might be a responder or non-responder would therefore save quite a lot of time, effort and expense.

Chronological age was identified as potentially being a factor influencing response to the GFCF diet, and in particular, those children aged between 7 and 9 years old as being potential best responders. I have to say that I am still mystified by this finding. Traditionally, I'd always assumed that there was a 'younger, the better' sentiment when applied to the possible effectiveness of dietary intervention on cases of autism, as per the rising tide of literature on other early interventions. Outside of the relatively small participant numbers we included for study, this could mean that there is some tie-in with the ADHD symptoms which seem to be targeted, bearing in mind my relative inexperience when talking about the manifestation of ADHD throughout childhood. In light of the recent case study from Dr Martha Herbert on a GFCF diet morphing into a ketogenic diet (see here), I do wonder if there might be other comorbidities also being affected which might also have some tie-in too. Who knows.

I don't think we have made any startling discoveries with the publication of this paper. We were limited to the variables that we examined over the course of the study and so were unable to talk about whether other, more diet-relevant factors such as coeliac disease (CD) or related pathology - non-coeliac gluten sensitivity for example - might also be involved in response to diet. This was a major shortcoming of our original paper I'll freely admit.

That we found that inattention and hyperactivity might be key factors in dietary response however, is to my mind, potentially very important. That targeting such behavioural issues might also have a knock-on effect to more core autism presentation (as per our ADOS results on communication) is also an area requiring further investigation and perhaps reflects how autism (or should that be the autisms) is so very much more than just the formal clinical descriptions we give it. RDoC anyone?

Blogging about ones own peer-reviewed research is something that I've always been a little bit hesitant about doing. Aside from the possible charge of self-publicity and the natural tendency to think that yours is obviously an important paper (who wouldn't think that about their own work?), one might argue that important features such as the objectivity required for good science blogging, might to some degree be compromised. Sort of like marking your own homework as per one of my colleagues oft-cited phrases. I very much hope that I've not over-stepped the mark on good science blogging in this post on Lennart's paper. Indeed I'll end by reiterating part of the opening sentence to this post on the requirement for independent replication before anyone gets too excited about these results, as indeed the dietary research base as it presently stands is in need of more inquiry********.

And since we're on the topic of diet and autism, would that be one hump or two*********?

ABOUT AUTISM SPECTRUM CONDITIONS

Autism or autism spectrum conditions describe several presentations characterised by core issues with social affect and stereotyped or repetitive actions. Diagnosis is made by observation and analysis of developmental history. These are heterogeneous conditions which can carry various co-morbidities and whilst described as life-long are affected by age and maturation. Autism means different things to different people. To some it means a need for life-long support. To others it is part of the varied tapestry of humanity. To all it means a need to foster a welcoming society with appropriate support and opportunities.